This invention pertains generally to solid state amplifiers for use at microwave frequencies and particularly to amplifiers of such type using IMPATT diodes as the active elements.
Advances in solid state technology have led to the design of solid state transmitters capable of providing greater than 500 watts average power at microwave frequencies. To attain such a power level with known IMPATT diodes, it is necessary to combine the outputs of a plurality of such diodes in a manner, for example, shown in U.S. Pat. No. 4,097,823 (Jerinic et al, issued June 27, 1983 and assigned to the same assignee as this application). It has been found, however, that the instantaneous bandwidth of the just-cited solid state transmitter is limited by the bandwidth of the driver (or locking) stage because the loaded Q of the driver stage is much higher than the loaded Q of any "power combining" stage.
In many applications a limited bandwidth is not desirable. For example, in an application wherein frequency agility is a requirement, limitation of the bandwidth of a solid state transmitter by the driver stage (rather than by any "power combining" stage) is to be avoided.